The communications industry long has promised a future where wireless service, video and the Internet are offered in one convenient package. Three huge possible deals now are bringing that future into view.

Cellphone and Internet provider AT&T Inc. is looking to buy satellite company DirecTV. Cable and Internet provider Comcast Corp. is considering offering mobile-phone service over Wi-Fi if its planned $45 billion merger with Time Warner Cable Inc. is approved. And cellphone company Sprint Corp. says it could provide...